please show all formulas labeled and very descriptive

12. Valerie and Parker each borrowed an identical amount. The nominal interest rate is 8.4% convertible monthly for both of these women. Valerie will repay her loan with 60 equal monthly payments of 81.46. Valerie's first payment is due one month from today. Parker will repay with 20 equal payments of 250 at times t = 1.21.3T,..., 20T That is, her payments are equally spaced in time, with the first to be T years from now. Note that T is in years. Determine the time elapsed between Parker's fifth payment and her 18th payment. 12. Valerie and Parker each borrowed an identical amount. The nominal interest rate is 8.4% convertible monthly for both of these women. Valerie will repay her loan with 60 equal monthly payments of 81.46. Valerie's first payment is due one month from today. Parker will repay with 20 equal payments of 250 at times t = 1.21.3T,..., 20T That is, her payments are equally spaced in time, with the first to be T years from now. Note that T is in years. Determine the time elapsed between Parker's fifth payment and her 18th payment